Electric motor



Feb. 16, 1932. J. zTscHE ETAL ELEGTRI C MOTOR Filed June l, 1929Patented Feb. 16, 1932 UNITED STATES PATENT OFFICE JONNY ZETSCHE ANDNICLAUS IETERSEN, F

HAMBURG, GERMANY, AND JAMES SINCLAIR-ROSS, 0F LONDON, ENGLAND; SAIDIETERSEN ASSIGNCR T0 SAID ZETSCHE .AND SAID lSINCLAIR-ROSS Applicationled ll'une 1, 1929, Serial No. 367,689,

This invention relates to electric motors the stationary and movingelements of which are provided with separate coils and has for itsobjectto provide an improved construction. of electric motors of this kind.

` Small high speed specially constructed electric motors have heretoforebeen employed, for driving gramophones for example, in which the mo-tionhas been transmit- 10 ted to the axle of the disc or turntable either bymeans of a gearing, for example' through a worm, or by a belt drive; insome cases also the motor is directly coupled with the said axle.` Ithas been found however that owing l5 to the high speed the motorbearings generally become quickly worn out and in the case of motorsdriven by alternating Current irritating noises are thereby produced.Further in order to adapt the known motors for use in connection withall ordinary voltages a regulating resistance is required, and the driveis consequently expensive and isapt to produce disturbances inoperation.

' Electric motors for use with gramophones, for example, in which thestator and rotor are provided with separate coils mechanically wound,and therefore relatively cheap, arc also known, but with these motorsalso various disadvantages have been found preventing their generalintroduction.

The improved construction of electric motors of the above indicated kindaccording to this invention may be applied both to small sizes of motorsfor driving light machinery, such as gramophones, and also to mediumAand large sizes for heavier work, and is characterized hereby, that thewindings as a whole are adapted for connection to the maximumdistribution voltage ordinarily met with and the stator and rotor coilsare arranged to form two mutually complementary magnetic circuits .ofthe horse-shoe type, the motor being adapted for connection to any lowersupply voltage, or to run at various speeds with a given supply voltage,simply by changing the grouping of the separate coils without requiringany series resistance, so that the motor works, for example, as atwo-pole, or four-pole, series-wound, shuntwound, or compound-woundmachines, and

ELECTRIC MOTOR and in Germany June 8, 1928.

with alternating current can be run as a repulsion motor.

A 'form of the improved motor construction is illustrated as an examplein the accompanying drawings in which Fig. 1 is a partly sectional sideview;

Fig. 2 is a plan.

Referring to the drawings, the field winding consists, in the exampleshown, of four separate coils 1, the cores 2 of which are mounted uponthe iron base plate 3 near the periphery ont the same and equidistantlyfrom one another. The coils 1 are helically wound on bobbins 4 and maybe connected in pairs in parallelv so as to produce alternately northand south poles, or they may be connected in series and so as to producetwo or four field poles, the desired connections being effected by meansof contacts 5 of a governing switch and one or more suitable movingcontacts (not shown) co-operating therewith.

The lower ends of the cores 2 are preferably countersunk and in closeconnection with the iron base plate 3, while the upper ends of the'cores are all interconnected by a closed iron ring 6. Thus all the lowerends of the field cores 2 are magnetically connected by the base plate 3and all the upper ends of the said cores are magnetically connected bythe ring 6, which preferably is of approximately triangular crosssection with the inner side of the triangle forming a vertical wall asshown at 7.

The rotor consists of a member 8, which for example may be a disc, keyedupon the vertical spindle 9 which is adapted to rotate upon a stepbearing 10 housed in the base plate 3, the upper part of the spindle 9being supported in a central bearing 11 of a metal top plate 12 which isarranged parallel to the base plate 3 and rigidly secured thereto bybolts or the like 13.

The rotor disc 8 carries a number of coils 14 wound upon bobbins 15 andarranged equidistantlyfnear the periphery of the disc, the cores 16 ofthe rotor coils being fixed at their upper `ends to the underside of thedisc 8. In the example illustrated twelve rotor coils 14 are shown, butany desired and convenient number may be provided. Thus the upper endslil or the cores 16 are all magnetically interconnected by the iron disc8, while the lower ends or the said cores are magneticallyinterconnected by a closed iron ring 17 formed with a vertical outersurface adapted to rotate in close proximity to the vertical surface 7of the ieldrin'g 6 as indicated at 18.

rIhe rotor coils, in the arrangement shown, are connected in series byavcommutator 19 having-the same number of seginentsasthere Vare rotorcoils. Theberinning or each coil is connected to the appropriate segmentof the commutator and theend of that-coil vis connectedto the nextfollowing segment to which also'the'beginning or' the next rotor coil isconnected', and so on through the whole or the rotor coils. Thecommutator is carried by, and insulated from, the vertical spindle `9,while a'set ot'tour brushes 2O is provided,

which `brush'esyare containedfin hollow cylindrical brush-holders 2lsuitablyy supported upon and insulated from the base plate 3, thebrushesl 20 being acted uponby springs so ask to continuouslypressuponithe commultator "19. v,Current is supplied=to therotor through'theterminals 22 which .are in elecvtrical connection with the brush holders21 'and thence with the brushes 20.

` The upper end 23 of the vertical spindle 9 is provided with a pulley24 which may be con- 1 nected tothe driven part by means of a suitabletransmission belt. Y 'The magnete lines of force of the individual coilsare Vperfectly combined by the closed yiron rings in such a wayithatauniormfrunning'rreefrom disturbances is obtained. Even with alternatingcurrent of high frequencies the run'ningroil the motor is noiseles'sexcept for' the usual Vyslight humming inseparable .trom `a rotorrevolving at high speed. l It will of course be understood'that thelmotor can' be worhedin any desired position and that the arrangement ofthe motor upon `a horizontal base and with a vertical spindle is vonlyselected-`for convenience of illustration and description.

l vWhat we claim and desire tosecure byLet- 4l. In anelectric motor, incombination, a stator'comprising a base plate of iron, a number ofseparate coils wound upon cores each with one end in magnetic contactwith Vthe 'base plate, a vclosed iron ring connecting the other ends ofthe stator cores,a rotor' base ,member of iron supported so -vas torotate in a plane parallel to that ofthe stator base plate, a kpluralityof separate coils wound u'poncores each with one end in magnetic contactwith the` rotor'base membena closed y -iron ring connecting the otherends` oit the rotoreores arranged to rotatein closeprOXmY -to 'the'corresponding ,statorv ring, and means for supplyingan electric currentto the stator I'and rotor coils. Y Y

ffarotor :red-*upon said shaft'compr-isingfa ladjacent the field coilsand equi-distant from Y the axis of the shaft and from one another,

cores' or said rotor coilsfea'ch with one end 80 in magneticcontactpwith saiddisc, aclosed ring of magnetic Amaterial connectingtheother ends of therotor cores andarranged/to Vrotatein lcloseproximity-.to the corresponding stator ring, and Vmeans for supplying anelectric current tothe statorl and rotorcoils.

3. AInan electric motor, in combination, a stator element comprising aniron base. plate, a number of separate coils thereon with cores arrangedto Jforma-magnetic circuit ofthe fhorse-shoe type, arotor velementcomprising a :shaft carrying .an Viron disc arranged `to 'rotate inavplane parallelfto the base plate,

a number otsepa'rate coils onfsaid ydise with cores varranged to `form asecond magnetic.-v

`circuit of the horse-shoe type complementary to the stator magneticcircuita closed polering or iron connecting the ends of the statorcoresv remote from the base plate, a closed pole-ring` of ironconnecting. theends ot'the- `rotor cores adjacent the said statorpole-ring,

and means for supplying an electric current to the stator and rotorcoils.

v4. In an electric motor, in combination, a stator element consistingofva number of sep-i5365 Zarate coils wound upon cores inimagneticcontinuity withone another, a rotor element also' consisting of a-numberot separate coils wound upon cores in magnetic continuity withone another, a closed iron ring fixedl 130311@ land completing the.magnetic circuit .of the stator cores, anda closed iron ring fixed toand completing the magnetic circuit of,V the rotor cores'and arrangedtorotateinclose '1 proximity to the stator ring, :andmeansfor??L5supplying an electric current to thestatorand yrotor coils. y

5. In an electric motor, in combination, a stator element coinprising'aniron basefand. 3fg av number of separatecoils wound upon iron "1cores'united to the said base, a rotorelement comprising an iron disclanda. number of sep- -arate coils wound upon iron cores united to saiddiscand arranged so as tobe magnet-25 ically complementary to the tieldor the stator element,` an iron shunting member united to the statorcores so .as to connect them all in V.a completely closed ironcircuit,fand.an iron shunting` member united to the rotor cores sol mi*tures.

JAMES SINCLAIR-ROSS. JONN Y ZETSCHE. In testimony whereof, I afx mysignature.

NICOLAUS PETERSEN,

CERTIFICATE 0F CORRECTICN.

Patent No. 1,845,386. Granted February 16, 1932, to

It is hereby certified that the name of the first named patentee in theabove numbered patent was erroneously written and printed as "JonnyZetsche", whereas said name should have been written and printed asJonui Zetsche; and that the said Letters Patent should be read with thiscorrection therein that the same may conform to the record of the casein the Patent Office.

Signed and sealed this 22nd day of March, A. D. 1932.

M. J. Moore, (Seal) Acting Commissioner of Patents.

CERTIFICATE 0F CGRRECTION.

Patent No. 1,845,386. Granted February 16, 1932, to

lt is hereby certified that the name ofthe first named patentee in theabove numbered patent was erroneously written and printed as "JonnyZetsche", whereas said name should have been written and printed asJonni Zetsche; and that the said Letters Patent should be read with thiscorrection therein that the same may conform to the record of the casein the Patent Office.

Signed and sealed this 22nd day of March, A. D. 1932.

M. J. Moore, (Seal) Acting Commissioner of Patents.

